1. Field of the Invention
This invention relates generally to hydraulic apparatus and more specifically to a system for testing hydraulic devices of various types.
2. Prior Art
It has been common practice in the art to test hydraulic components, sub-systems and systems (hydraulic devices) subsequent to their assembly to ascertain whether the hydraulic device is operating in accordance with the specifications set forth for it. For example, it is typical to connect a hydraulic actuator to a test stand and determine its frequency response, external and internal leakage, proof pressure, ram travel and velocity, damping, hysteresis and the like. In such prior art test stands, the individual ports to which the hydraulic apparatus under test is connected are dedicated ports. That is, each of the ports functions to provide a source of hydraulic fluid under pressure or its return to which the hydraulic device under test may be connected. It is never possible, without substantial rerouting of the hydraulic plumbing, to change a particular port from a pressure port to a return port or vice versa. As a result, each hydraulic test stand has been severely limited as to the hydraulic devices which could be tested on that particular test stand.